Method of extracting resinous material from plant tissue



Patented Nov. 15, 1932 tillation.

type-of apparatus for its use. ow,- in accordance with'my invention, I

UNITED STATES PATENT OFFICE LEAVITT N. BENT, OF HOLLY OAK, DELAWARE, ASSIGNOR TO HERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE METHOD OF EXTRACTIATG RESINOUS MATERIAL FROM PLANT TISSUE Io Drawing.

My invention relates to a method for extracting rosin from wood.

As is well known, a principal source of rosin is in stumps and down Wood of the long leaf pine harvested from cut over lands and subjected in a comminuted state to treatment for the removal of turpentine and pine oil and then to extraction with gasoline, which acts to dissolve out rosin.

In accordance with prior practice the stumps and down wood are comminuted to a suitable size and loaded into retorts or extractors in which the turpentine and partvof the pine oil are removed by the use of live steam. The wood is then subjected to extraction with a solvent, as a low boiling petroleum hydrocarbon, which acts to dissolve out the remaining pine oil and the rosin. The solvent is finally separated from the spent wood by steaming and rosin and pine oil are recovered from the solvent by fractional dis- Such a process is for example, more fully described in the S. patent to Yaryan No915,400. Y

Heretofore in theextraction of rosin from wood, it has been deemed essential to utilize a solvent which is immiscible with water, as, for example, a light hydrocarbon solvent, since water resulting from the presence of moisture inthe wood, from condensation of the steam used for extraction of the turpen-' only about 75% of the resinousmaterial pres ent in the wood, and that when heated it constitutes a fire risk and requires a effect the extraction of the resinousmaterial from wood by the use of 'acold, water miscible solvent, and more particularly,such a solvent mixed with a certain amountof water, the concentrationof the solvent being such that it will dissolve out all of the resinous matparticular ters from the woodand at the same time of a concentration such that when further diluted, as by moisture in the wood, it may be re covered in substantially its original concentration by distillation from a simple still.

As solvents, the use of which I contemplate in accordance with my invention, maybe mentioned, for example, acetone, alcohol, methanol and the like, and the treatment'of the wood with one or another of the water miscible solvents in accordance with my inion filed iebruary 15, 1928. Serial No. 254,622. E D

vention may be in accordance'With the usual I I practice at atmospheric or increased pressure and with the use of'any' ordinary or desirable form of apparatus. The solvent when used will, as has been indicated, be mixed with water to a concentration enabling its 'recovcry at substantially its original concentration by distillation from a simple still and depending upon the particular solvent selected" maybe mixed with water to aconcentration of solvent" Within, for example, about'the range 65%90%. More specifically, acetone may be desirably used at a concentration ofabout alcohol at about and methanolat about 80%.

As aspecific example 'of the'carryingout of themethod in accordance with my'inven tlon wood chips, which normally contain about 15% 18% of moisture, are steamed in the usual manner for distillation off of turpentine', and after steaming will contain about 20%25% of moisture. The wood chips after steaming are extracted with, for example, acetone mixed'with water to a con centration of about 75%." The acetone-during the process of extraction'and solvent "re-i from 7 5%.to about-70% and. may be comcovery will pick up suflicient moisture from i the wood. chips to reduce itsconcentration pletely recoveredas 80% acetone byrunning' Y i it through a simple still in which thesolvent, I

will be separated from therosin extracted;

a solution of acetonein water of a conoentra.

tion of say; forexample, 86% acetdne: "Dur ing the extraction heat may be applied,

thoughit will be understood that the application of heat is not necessary. I The extraction ma be carried out at atmospheric pressure. liter a suitable period the acetone solution, together with extracted rosin, 1s drained from the wood and the wood may be 're-extracted with sa 235 pounds of 86% acetone solution, which inturn is drained from the wood and, if desired, third, fourth and even fifth extractions may be efiected. Extraction with 86% acetone solution, using say five extractions, will be found 'to remove from 99% to 100% of the acetone soluble rosin, or about 23 pounds in the foregoing example.

As an alternative method there may be added to, the dilute acetone solution of rosin suflicient butane, pentane, or bther water immiscible low boiling petroleum hydrocarbon, which is not miscible with the solvent, as acetone, used for extracting the W00(l, and which has a greater solvent power on the rosin than has the solvent used for extraction of the wood in aclosed vessel to prevent the volatilizing of the butane, to extract from this dilute acetone solution of rosin the rosin content. Butane and dilute acetone being substantially immiscible, two layers will be formed on settlement, the upper layer being a butane solution of rosin, the lower being a dilute acetone solution containing dark colored resinous bodies. The lower layer 1s drawn ofi and distilled to rid it of the excess water picked up from the wood chips, and for the recovery of dark colored ros n and other extracted-materials which are soluble in acetone but not soluble in butane. The upper layer is distilled to recover the butane for re-use and separate it from the rosin. The acetone recovored from the wood chips by steaming will be found to be of about concentration and may be recovered completely as a 68% acetone by running it through a simple still in which rosin willibe separated out. The two recovered solvents are after recovery added together and produce an acetone of 74% concentration or approximately of the same concentration as the origmal acetone and available for re-use in extraction.

The method according to my invention, and more especially the use of a water mis cible solvent, will enable the extraction of substantially all the resinous matter from wood chips and while the .rosin recovered will be foundto be darker than that obtained by prior methods, it may be readily purified to. a common or superior grade of rosin by distillation, by treatment with selective solvents, by treatment with decolorizing earths or charcoal or-by other known methods. Further, due to the high percentage extraction of rosin, the spent wood chips will be found more suitable foruse, for example, in the manufacture of paper pulp, and the like, than heretofore.

It will be understood that the figures given in the above example may vary considerably in practice for various reasons, such as the molsture content ofthe wood chips treated, the quality of steam used, the size of the extractor, etc., and it will be appreciated'that generally speaking efiiciency will be promoted by a high ratio of solvent to wood and 75 a maximum concentration of solvent within limits enabling recovery of the solvent as described. I

It will be understood that in carryin out the process according to my invention, contemplate not onl the use of a simple still for the recovery of the solvent, but also the use ofcontinuous evaporators or other form of apparatus.

Having now fully described my invention, 35 what I claim and desire to protect by Letters Patentis I 1. The method of extracting rosin from resinous wood, which includes extracting the; wood with an organic aliphatic solvent form the rosin which is miscible with water, adding a low boiling petroleum hydrocarbon, which has selective solvent power on therosin and which is immiscible and non-reactive with the first mentioned solvent, to the solution of rosin obtained, separatin the low .boiling petroleum hydrocarbon an dissolved rosin om the original solvent and distilling off the low boiling hydrocarbon for the recovery of rosin.

2. The method of extracting rosin from resinous wood, which includes extracting the wood with an alcohol solvent for therosin,

adding a low boiling petroleum hydrocarbon,

which has a selective solvent power on the ros n, to the solution of rosin obtained, separating the low boiling petroleum hydrocarbon and dissolved rosm from the alcohol and distilling ofi the low boiling by hydrocarbon for the recovery of rosin. 0 The method of extracting rosin from resinous wood, which includes extracting the wood with a monohydric alcohol a solvent for the resin, addin a low boiling petroleum hydrocarbon, whic has a selective solvent 116 power on the rosin, to the solution ofrodn obtained, se arating the low boiling petroleum h'y rocarbon and dissolved rosin from the monohydricalcohol and distilling off the low boiling hydrocarbon for the re- 120' covery of rosin.

The method of extracting rosin from resinous wood, which includes extracting the wood with methyl alcohol a solvent for the rosin, adding a low boiling petroleum hydrocarbon, which has a selective solvent power on the rosin, to the solution of rosin obtained, sgparating the low boiling troleumhy rocarbon and dissolved rosin from the monohydric alcohol and I ofi'the low boiling hydrocarbon for the recovery of rosin.

5. The method of extracting rosin from pine wood which includes extracting the wood with a water miscible organic aliphatic solvent diluted with water to a concentration within the range 65 %90%, extracting rosin from the solution obtained with a low boiling petroleum hydrocarbon which is immiscible and non-reactive with the solvent, separating the low boiling petroleum hydrocarbon and extracted rosin fr m the original solvent and distilling ofi' the low boiling hydrocarbon for the recovery of rosin.

6. The method of extracting rosin from pine wood which includes extracting the wood with a water miscible organic aliphatic solvent diluted with water to a concentration within the range 65 76-90%, extracting rosin from the solution obtained with a low boiling petroleum hydrocarbon. which is immiscible and non-reactive with the solvent, separating the low boiling petroleum hydrocarbon and extracted rosin from the original carbon for the recovery of rosin and distilling the original solvent.

7. The method of extracting rosin from pine wood which includes extracting the wood with an alcohol diluted with water, extracting rosin from the solution obtained with a low boiling petroleum hydrocarbon which is immiscible with the diluted alcohol, separating the low boiling petroleum hydrocarbon and extracted rosin from the original solvent and distilling off the low boiling hydrocarbon for the recovery of rosin.

8. The method of extracting rosin from pine wood which includes extracting the wood with methyl alcohol diluted with water, extracting rosin from the solution obtained with a low boiling petroleum hydrocarbon which is immiscible with the diluted methyl alcohol, separating the low boiling petroleum hydrocarbon and extracted rosin from the original solvent and distilling off the low boiling hydrocarbon for the recovery of rosin.

9. The method of extracting rosin from pine wood which includes extracting the wood with an alcohol diluted with water to a concentration of about extracting rosin from the solution obtained with a low boiling petroleum hydrocarbon which is immiscible with the diluted alcohol, separating the low boiling petroleum hydrocarbon and extracted rosin from the original solvent and ble with the solvent used, to the solution of rosin obtained, separating the low boiling etroleum hydrocarbon and dissolved rosin rom the original solvent and distilling off the low boiling hydrocarbon for the recovery of rosin.

11. The method of extracting rosin from pine wood which includes extracting the wood with a water miscible organic aliphatic solvent for the rosin diluted with water, ex- 7 tract-ing rosin from the solution obtained with a low boiling petroleum hydrocarbon which is immiscible and non-reactive wit-h the solvent used and separating the low boiling petroleum hydrocarbon and extracted rosin from the original solvent, and distilling ofl the low boiling hydrocarbon for the recovery of rosin.

12. The method of extracting rosin from pine wood which includes extracting the wood with acetone diluted with water, extracting rosin from the solution obtained- With a low boiling petroleum hydrocarbon which is immiscible wit-h acetone, separating the low boiling petroleum hydrocarbon and extracted rosin from the original solvent and distilling off the low boiling hydrocarbon for the recovery of rosin.

13. The method of extracting rosin from pine wood which includes extracting the wood with acetone diluted with water, extracting rosin from the solution obtained with butane, separating the butane and extracted rosin from the acetone and distilling off the butane for the recovery of the rosin.

In testimony of which invention, I have hereunto set my hand at Wilmington, Del., on this 11th day of February, 1928.

LEAVITT-N. BENT.

distilling oil the low boiling hydrocarbon for r the recovery of rosin.

10. The method of extracting rosin from pin wood which includes extracting the wood with an organic solvent for the rosin which is miscible with water, adding a low boiling petroleum hydrocarbon, which has greater solvent power on the rosin and which is immisci- 

